1. Field of the Invention
This invention relates to a coordinate reader which utilizes a delay time of a magnetostrictive oscillation wave propagating in a magnetostrictive plate.
2. Description of the Prior Art
A device of this kind comprises an input panel, an input pen and a controller and has widely been employed mainly as an input device for graphic data processing in the fields of electricity, communication, machinery, instrumentation, meteorology, medical science, etc. Such a device now rapidly comes into wide use, since it has a high resolution of about 0.25 mm and is highly reliable and inexpensive. However, the conventional device of this kind has a defect such that the accuracy of the measured coordinates is markedly lower at the peripheral part of the input panel as described below.